MAX17681

4.5V to 42V Input, High-Efficiency, Iso-Buck DC-DC Converter

Reduces External Components and Cost for DC-DC Isolation


Description

The MAX17681/MAX17681A is a high-voltage, highefficiency, iso-buck DC-DC converter designed to provide isolated power up to 5W. The device operates over a wide 4.5V to 42V input and uses primary-side feedback to regulate the output voltage.

MAX17681/MAX17681A uses peak-current-mode control. The low-resistance, on-chip MOSFETs ensure high efficiency at full load while simplifying the PCB layout.

The MAX17681/MAX17681A devices generate a well regulated primary side voltage which is then scaled by a suitable transformer turns ratio to derive isolated secondary output rails. While both MAX17681 and MAX17681A support primary side overcurrent protection, the MAX17681A is an enhanced design that supports robust secondary-side overcurrent protection as well.

The MAX17681/MAX17681A is available in a compact 10-pin (3mm x 2mm) TDFN package. Simulation models are available.

MAX17681: Block Diagram MAX17681: Block Diagram Enlarge+

Key Features

  • Reduces External Components and Total Cost
    • No OptoCoupler
    • Synchronous Primary Operation
    • All-Ceramic Capacitors, Compact Layout
  • Reduces Number of DC-DC Regulators to Stock
    • Wide 4.5V to 42V Input
    • 0.9V to 0.96 x VIN Primary Output Voltage
    • Delivers Up to 5W Output Power
  • Reduces Power Dissipation
    • Peak Efficiency > 90%
    • 0.9µA (typ) Shutdown Current
  • Operates Reliably in Adverse Industrial Environments
    • Peak and Sink Current-Limit Protection
    • Robust Secondary-Side Output Overcurrent Protection (MAX17681A)
    • ±1.7% Feedback Accuracy
    • Programmable EN/UVLO Threshold
    • Adjustable Soft-Start
    • Overtemperature Protection
    • -40°C to +125°C Operation

Applications/Uses

  • Floating Power Supply Generation
  • Isolated Fieldbus Interfaces
  • Isolated Power Supplies in Medical Equipment
  • PLC I/O Modules
  • Smart Meters
Part Number Application (VIN) VIN
(V)
VIN
(V)
Topology Switch Type Feedback Freq.
(kHz)
Duty Cycle
(%)
ISTARTUP
(mA)
ICC
(mA)
Design Tools Oper. Temp.
(°C)
Package/Pins Budgetary
Price
min max max max max See Notes
MAX17681 
Base Station (24V)
Industrial (24V)
4.5 42 Flyback Internal Primary Side 200 97.5 2.8 2.8 EE-Sim -40 to +125
TDFN/10
$1.40 @1k
See All Isolated Power Supplies (24)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.


MAX17681EVKIT: Evaluation Kit for MAX17681 Isolated ±15V or ±12V Output Configuration
MAX17681EVKITC: Evaluation Kit for the MAX17681 Isolated +15V or +12V Output Configuration
MAX17681EVKITD: Evaluation Kit for the MAX17681 Isolated +7V or +5V Output Configuration
MAX17681EVKITF: Evaluation Kit for the MAX17681 Isolated +24V Output Configuration
MAX17681EVKITB: Evaluation Kit for the MAX17681 Isolated ±7V or ±5V Output Configuration
MAX17681EVKITE: Evaluation Kit for MAX17681 Isolated ±15V and ±7.5V Output Configuration

Technical Documents

Brochure 6362 Powering the Pocket IO PLC Development Platform
User Guide 5861 EE-SIM Design and Simulation Environment User Guide

Quality and Environmental Data

Product Reliability Reports: MAX17681.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

Topmark Coding MAX17681

Tools & Models

Design & Simulate MAX17681

Related Resources

Type ID Title
System Board6330MAXREFDES150# Pocket IO PLC Development Platform
Evaluation Board9053MAX17681EVKITE Evaluation Kit for MAX17681 Isolated ±15V and ±7.5V Output Configuration
Evaluation Board9028MAX17681EVKITB Evaluation Kit for the MAX17681 Isolated ±7V or ±5V Output Configuration
Evaluation Board9022MAX17681EVKITF Evaluation Kit for the MAX17681 Isolated +24V Output Configuration
Evaluation Board9021MAX17681EVKITD Evaluation Kit for the MAX17681 Isolated +7V or +5V Output Configuration
Evaluation Board9020MAX17681EVKITC Evaluation Kit for the MAX17681 Isolated +15V or +12V Output Configuration
Evaluation Board8751MAX17681EVKIT Evaluation Kit for MAX17681 Isolated ±15V or ±12V Output Configuration